Electrical socket



June 22, 1948. A. M NABB ELECTRICAL SOCKET Filed July 27, 1945 INVENTDR LEILIIS AMBNABB amfi x. 'ATT'Y.

Patented June 22, 1948 2,443,743 ELECTRICAL sooKa'r Louis A. McNabb, Glenview, 111., assig'nor to Bell & Howell'- Company, Chicago, 111., acorporation :Application-July-27, 1945,,s r'ial No. 607,442

My invention. relates particularlyv to an electri cal socket adapted to receive the standard payonet time base of anincandescentelectriclamp or. the like,a nd objectsthereof residelin the provision of a novel and efectiveelectrical-socket which is adapted to accurately and rigidly position an incandescent electric lamp thereon and which provides for. the convenient mounting of the lamp on the socket and the removal of the lamp therefrom, the invention being of particular value where the filament of the lamp is required to beaccurately positioned as isthedcase with exciter lamps of photographic sound translating devices.

The invention will be better understood by ref eren-ce to the accompany-ingdrawing forming a part hereofand in which-- I f f Figure 1 is a sectional viembf an electrical socket embodying my invention and takensubstantially on the line l-I of Figure 3 and having an incandescent electric lamp mounted thereon;

Figure 2 is a sectional view taken substantially on the line 22 of Figure 1;

Figure 3 is a sectional view taken on the line 3-3 of Figure 1; and

Figure 4 is a partial perspective view of the lamp base receiving tubular member of the socket hereinafter described.

Referring to the drawing, a support part I is provided with a bore 2, and secured in this bore is a tubular metallic member ,3 which forms the circumferential contact of the socket and the bore 4 of which is adapted to receive the cylindrical base, generally designated at 5, of an incandescent lamp 6 of usual construction, the base having a usual circumferential metal shell I forming the peripheral contact of the lamp base and having a usual end contact 8. The shell I and the end contact 8 are connected to opposite terminals of the'filament of the lamp, not shown, in a usual manner.

The tubular member 3 is provided with a usual bayonet slot 9 extending downwardly from the upper end thereof, and is also provided with a second slot II extending downwardly from the upper end thereof in diametrically opposite relation with the bayonet slot. The second slot II, while being of bayonet slot formation, does not function as a bayonet slot and serves only for clearance purposes as will hereinafter appear, the transverse lower portion thereof being of considerable height as designated at I2 in Figure 4.

The lamp base is provided with standard diametrically opposite bayonet pins I3 which respectively engage in the slots 9 and II when the realm. (01. 173-328) lamp base is received in the tubular member 3, and the bayonet pin which engages in the slot Qaxially'interlocks the lamp base in the tubular member by its engagement in the transverse lower portion I4 of the slot 9 as best shown in Figure 2, the slot I'I merely providing clearance for the other bayonet pin.

An end socket contact I5, provided with a cirquit wire IE, is carried on a washer ll of insulating material which is slidably engaged in the bore 4 of the tubular member 3', and a compressicn spring I3 is operative between the washer l1 and a shoulder I9 of'the bore 4 to urge the end contact I5 into engagement with the end contact 8 of the lamp base 5 when the lamp base is interlockedwith the tubular member 3, as shown in Figures 1 and 2.

The diameter of the bore 4 of the tubular member 3 is somewhat larger than that of the lamp base 5, as best shown in Figure 3. The tubular member 3 is provided with two stationary clamping elements 2I formed integrally therewith by extrusion and angularly spaced about the tubular member and consequently about the socket axis. These clamping elements project radially inward from the internal surface of the tubular member 3 to peripherally engage the lamp base 5, and preferably, as shown, are in the form of ridges extending longitudinally of the axis of the tubular member 3and consequently of the socket axis to engage an appreciable longitudinal extent of the lamp base, to the end that when the lamp base is clamped thereagainst, as hereinafter described, the lamp is not only accurately and rigid- 1y positioned radially of the lamp axis but is also accurately and rigidly positioned angularly in axial planes of the lamp axis.

A third clamping element 22 in the form of a plunger is slidably mounted in a bore 23 of the support part I and, as so mounted, is movable radially of the tubular member 3 and consequently of the socket axis, and this plunger extends through the transverse portion I2 of the slot I I to peripherally engage the lamp base 5 as shown in Figures 1 and. 3. The clamping elements 2I and 23 are angularly spaced about the axis of the tubular member 3 and consequently of the socket axis and are thus adapted to peripherally confine the lamp base therebetween.

A lever 24 is disposed in a recess 25 of the support part I and is intermediately pivoted on the support part as designated at 26, as shown in Figures 1 and 3. One end of the lever 24 is engaged in a circumferential groove 2'! of the clamping element 22, and the other end of this lever is engaged in a circumferential groove 28 of a push plunger 29 slidably mounted in a bore 3| through a cover plate 32 secured on the support part I and covering the recess 25. A compression spring 33, within the recess 25, is operative between the tubular member 3 and the lever 24 to yieldably urge the clamping element 22, through the medium of this lever engaging the groove 21, in the direction radially inward of the tubular member 3 and thus clamp the lamp base 5 between the clamping elements 2| and 22 for accurately and rigidly positioning the lamp 6. The clamping element 22 engages the lamp base intermediate the extent of the clamping elements 2| so that the lamp base is clamped against the clamping elements 2| throughout their extents. Accordingly, the lamp 6 is accurately and rigidly positioned radially of the lamp axis and angularly in axial planes of the lamp axis, the shell 1 of the lamp base being in contact with the tubular member 3 through the medium of the clamping elements 2|.

The push plunger 29 is provided with a head 34 exterior of the cover plate 32 by means of which the plunger may :be manually actuated inwardly, and, through the medium of the lever 24 engaging the groove 28, this actuation of the plunger effects movement of the clamping element 22 radially outward of lamp base clamping position to facilitate insertion of the lamp base 5 in the socket and the removal of the same therefrom, the lamp base engaging end of the clamping element 22 being rounded as designated at 35 also for facilitating insertion of the lamp base in the socket and the removal of the same therefrom.

While I have thus described my invention, I

do not wish to be limited to the precise details described, as changes may be readily made without departing from the spirit of my invention, but

having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

In an electrical socket, the combination with a tubular member provided with diametrically opposite bayonet pin receiving slots and adapted to receive a cylindrical lamp base or the like provided with diametrically opposite bayonet pins and one of said slots being a bayonet slot and an end contact member spring urged axially of said tubular member to engage an end contact of said base, of three base clamping elements angularly spaced about the axis of the socket and adapted to peripherally confine said base therebetween and between two of which said bayonet slot is intermediately disposed, said two clamping elements being fixed with said tubular member and projecting radially inward from the internal surface thereof and being extended longitudinally of said tubular member to engage an appreciable longitudinal extent of said base, and the third of said clamping elements being mounted exteriorly of said tubular member for movement radially thereof and disposed at and extendable through the other of said slots to engage said lamp base and yieldably urged in its base clamping direction.

LOUIS A. MCNABB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 298,143 Weston May 6, 1884 1,876,873 Douglas Sept. 13, 1932 2,233,146 Schwartz et al Feb, 25, 1941 

